In building structures it is often desirable to prevent fire from spreading. To that end, two enclosed spaces may be separated by a firewall. The firewall itself may support structural cross-members, such as floor joists for higher floors of the structure. In the event that those floor joists should move, it may be desirable for their dislodgement not also to cause the collapse of the firewall.
To that end, the inventor proposes herein to provide an end support for these beams or joists in the normal course, but then to permit the ends of the joists to release from the firewall in the event of a fire, with the hope that the firewall may then not be damaged and may be able to continue to perform its protective function as a firewall.